1. Field of the Invention
The present invention relates to an electrodeless lighting system and, more particularly, to a resonator of an electrodeless lighting system capable of increasing the size of a reflector reflecting light radiated from an electrodeless bulb, verifying forms of the reflector, and matching impedance of an electronic wave exciting gas-fill filled in the electrodeless bulb and controlling a resonance frequency.
2. Description of the Background Art
In general, in an electrodeless lighting system, gas-fill filled in an electrodeless bulb is excited to be converted into a plasma state, and a peripheral place is illuminated by light generated from plasma. The light generated by plasma is a natural light having an excellent illumination effect compared to the generally used incandescent electric lamp or a fluorescent lamp, and a life span of its bulb is longer.
FIG. 1 is a sectional view showing a general electrodeless lighting system, and FIG. 2 is a sectional view taken along line A-B of FIG. 1.
As shown in these drawings, the electrodeless lighting system includes: an microwave generator 10 for generating microwave energy; a resonator 20 having a resonating space 21 for resonating microwave generated from the electromagnetic generator 10; an microwave feeder 30 mounted in the resonating space 21 of the resonator and guiding microwave generated from the microwave generator 10 into the resonating space 21; an electrodeless lamp 40 positioned in the resonating space 21, connected to the microwave feeder 30, and generating plasma light by the resonated microwave energy; a reflector 50 for reflecting light generated from the electrodeless bulb 40 in a forward direction; and a transparent cover 60 mounted at a front side of the reflector 50 to prevent leakage of microwave and protect the electrodeless bulb 40.
The resonator 20 includes a main body 22 formed in a prescribed shape; the resonating space 21 formed in a cylindrical shape and having prescribed inner diameter and depth at one side of the main body 22; and a transmission space 23 formed communicating with the resonating space 21 in a vertical direction at one side of the main body 2, in which an antenna 11 of the microwave generator is positioned.
The resonating space 21 is opened at one side, and its inner diameter has a prescribed form. An inner circumferential surface of the resonating space 21 is coated with a dielectric material.
A coupling part 24 is formed at the opening side of the resonating space 21, to which the cover 60 is coupled. The coupling part 24 has prescribed depth and area, which are the same as the thickness and the area of the cover 60.
The microwave feeder 30 includes a first conductor bar 31 having a prescribed length, positioned in the transmission space 23 and connected to the antenna 11; and a second conductor bar 32 connected to the first conductor bar 31 and positioned at the center of the resonating space 21.
A conductor ring 70 for concentrate microwave is coupled at a boundary region between the resonating space 21 and the transmission space 23.
The electrodeless bulb 40 includes a bulb portion 41 filled with gas-fill and a stem portion 42 extended with a prescribed length from an outer circumferential surface of the bulb portion 41. The electrodeless bulb 40 is connected to the second conductor bar 32 in such a manner that the stem portion 42 is positioned to be level with the second conductor bar 32.
The reflector 50 includes a curved-surface portion 51 with a reflection surface at its inner side, a fixing portion 52 forming a circumference of the curved-surface portion 51 and coupled to the cover 60; and an insertion portion 53 formed at one side of the curved-surface portion 51, into which the stem portion 42 of the electrodeless bulb is inserted.
The reflector 50 is positioned at the open side of the resonating space 21 and encompasses the bulb portion 41 of the electrodeless bulb.
The cover 60 has prescribed thickness and area. When the cover 60 coupled to the reflector 50, it is coupled to the coupling part 24.
The electrodeless lighting system as described above is operated as follows.
First, when microwave is generated from the microwave generator 10 and oscillated through the antenna 11, the microwave is transferred into the resonating space 21 of the resonator through the microwave feeder 30. As the microwave is resonated in the resonating space 21, a strong electric field is formed at the electrodeless bulb 40 and the gas-fill filled in electrodeless bulb 40 is excited to generate plasma.
Light is emitted by plasma generated from the electrodeless bulb 40 and reflected by the reflector 50 to illuminate the front side.
In the electrodeless lighting system, the structure of the resonator 20 resonating microwave oscillated from the electromagnetic generator 10 is very critical to enhance a light efficiency by plasma. That is, the resonator should have a structure that a strong electric field resonated in the resonator 20 is formed at the side of the electrodeless bulb 40.
If the resonated strong electric field is not formed at the area where the electrodeless bulb 40 is positioned, longer time is taken to light and re-light the electrodeless bulb 40, and a light efficiency in generating light is degraded.
In addition, the electrodeless lighting system is expected to generate various outputs depending on a place where the electrodeless lighting system is installed and its purpose, and accordingly, the size or the shape of the reflector 50 reflecting light generated from the electrodeless bulb 40 needs to be varied in diverse forms.
However, the conventional electrodeless lighting system has the following problems.
That is, since the reflector 50 is positioned in the resonating space 21 of the resonator having a prescribed inner diameter, the size of the reflector 50 is limited and can be hardly changed to various forms. If the size of shape of the reflector 50 is changed, it is difficult to match impedance or control a resonance frequency by the resonating space 21.
In addition, since the reflector 50 is positioned in the cylindrical resonating space 21, the size of the reflector 50 is limited. Then, the amount of parallel light emitted from the electrodeless bulb 40 is reduced, making the illuminated region narrow, so the illumination efficiency deteriorates.